Background: The anatomical characteristics that predispose patients to present obstructive sleep apnea have not yet been fully established. Objective: To identify the possible association between obstructions of the upper airway observed in computed tomography and the presence of obstructive sleep apnea in adults. Method: Study of cases and controls with the approval of the ethics committee of the faculty of medicine at Pontificia Universidad Javeriana. Bogota and the Hospital San Ignacio, Colombia. A sample of 305 adults was selected with polysomnographic diagnosis for sleep disorders and underwent computed tomography, 205 individuals in the case group and 100 individuals in the control group. The obstruction was evaluated in the upper airway (transverse T and anteroposterior AP) for retrolingual, retrouvular area and changes in the upper airway. Results: When comparing the 61 individuals diagnosed with OSA moderate and control group, it was found that the retrouvular area retrouvular AP, retrouvular T, retrolingual and retrolingual AP were smaller than control both awake state and sleep group being statistically significant. For individuals with severe OSA. it was shown statistically significant difference for retrouvular area T, retrolingual and retrolingual AP, they found decreased both in awake state (p = 014), (p = .000), (p = .000) and sleep (p = 0.016), (p = 0.002), (p = 0.004) compared with the control group. No statistically significant differences were observed in moderate OSA, and control group, between awake and asleep state. OR was evaluated with a confidence interval of 95%, Individuals presenting the area retrouvular AP OR = 1.7 (1.22-14.14, p = 0.015) and T retrolingual area OR = 8.8 (1.00-77.56: p = 0.019) decreased they have a higher risk of moderate AOS. In severe OSA individuals with T retrouvular area decreased OR = 5.4 (1.01-29.13, p = 0 029) showed a higher risk. Conclusions: Individuals with OSA have the upper airway diminished mainly at the retrolingual area, which becomes more marked in patients with severe OSA. Keywords: obstructive sleep apnea, polysomnography, x-ray computed tomography